Fighting fires is a dangerous occupation, particularly when the fire is located in rugged terrain. Many factors contribute to this danger: Firefighting crews may have to travel on foot across open country without the benefit of roads or trails. Crews may have to travel across steep, mountainous terrain. In steep mountainous terrain, crews may have limited access to reliable communication. Fire managers located in a safe control operations area may not know the exact location of a crew. The information regarding a fire's location, speed, and direction of travel may be hours out of date and no longer accurate. The crew may not be aware of available safe zones, even if those safe zones are relatively nearby. The crew may not be aware of changing weather patterns. Crews often rely on lookouts or observation towers for information regarding the fire, which themselves may be abandoned for safety reasons. If a crew decides it needs to evacuate to a safe area, they may not know the fastest or the safest route to that safe area and they may have to guess if they can make it to the safe area ahead of the fire.
For at least the above reasons firefighters may find themselves in situations that are considerably more dangerous than anticipated. Knowing the fastest and safest route to a safe area may mean the difference between a frightening experience and tragedy. In order to predict whether or not a crew can make it from their current location to a safe area ahead of a fire, the firefighters need to be able to predict three things with some degree of accuracy: how fast the fire will travel, the direction in which the fire will travel, and how fast the crew will travel.